leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

tcp: fix tcp_xmit_retransmit_queue() after rbtree introduction

Browse Source 
I tried to hard avoiding a call to rb_first() (via tcp_rtx_queue_head)
in tcp_xmit_retransmit_queue(). But this was probably too bold.

Quoting Yuchung :

We might miss re-arming the RTO if tp->retransmit_skb_hint is not NULL.
This can happen when RACK marks the first packet lost again and resets
tp->retransmit_skb_hint for example (tcp_rack_mark_skb_lost())

Fixes: 75c119afe1 ("tcp: implement rb-tree based retransmit queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2017-10-16 19:38:35 -07:00 committed by David S. Miller
parent b082af73bf
commit b9f1f1ce86
1 changed files with 3 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
net/ipv4/tcp_output.c
View File

@ -2921,7 +2921,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
void tcp_xmit_retransmit_queue(struct sock *sk) void tcp_xmit_retransmit_queue(struct sock *sk)
{ {
const struct inet_connection_sock *icsk = inet_csk(sk); const struct inet_connection_sock *icsk = inet_csk(sk);
struct sk_buff *skb, *rtx_head = NULL, *hole = NULL; struct sk_buff *skb, *rtx_head, *hole = NULL;
struct tcp_sock *tp = tcp_sk(sk); struct tcp_sock *tp = tcp_sk(sk);
u32 max_segs; u32 max_segs;
int mib_idx; int mib_idx;
@ -2929,11 +2929,8 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
if (!tp->packets_out) if (!tp->packets_out)
return; return;
skb = tp->retransmit_skb_hint;
if (!skb) {
rtx_head = tcp_rtx_queue_head(sk); rtx_head = tcp_rtx_queue_head(sk);
skb = rtx_head; skb = tp->retransmit_skb_hint ?: rtx_head;
}
max_segs = tcp_tso_segs(sk, tcp_current_mss(sk)); max_segs = tcp_tso_segs(sk, tcp_current_mss(sk));
skb_rbtree_walk_from(skb) { skb_rbtree_walk_from(skb) {
__u8 sacked; __u8 sacked;